Amunix to Collaborate With Biogen Idec on Next Generation Long-Lasting Blood Factor Products

Amunix, Inc. today announced that it has entered into an
exclusive worldwide research collaboration and option agreement with Biogen
Idec to research and develop novel, fully-recombinant blood factors (Factors
IX, VIII and VIIa) with improved therapeutic properties. The partnership will
combine Amunix's protein half-life engineering expertise, based on its
proprietary XTEN technology, and Biogen Idec's broad range of capabilities in
research, manufacturing and clinical development of recombinant blood factors
for hemophilia.

"Biogen Idec is pleased to initiate research on this
innovative technology in collaboration with Amunix," said Glenn Pierce,
Senior Vice President of Biogen Idec Hemophilia
(http://www.biogenidechemophilia.com/home.php) . "We have a long-term
commitment to hemophilia. In addition to advancing our current late-stage long-lasting
Factor IX and Factor VIII programs, we continue to invest in innovations like
XTEN, which have the potential to bring further-improved treatment options to
the hemophilia community."

Under the terms of the agreement, the companies will jointly
conduct preclinical research. Biogen Idec will additionally be responsible for
clinical development, manufacturing and commercialization of therapeutic
candidates selected for further development. Amunix will receive an initial
upfront payment in addition to R&D funding. Amunix will also be eligible to
receive future milestone and royalty payments for therapeutic candidates chosen
by Biogen Idec for development. Additional financial terms will not be
disclosed.

"We are pleased to be collaborating with Biogen Idec, a
global leader in hemophilia therapeutics," said Willem 'Pim' Stemmer,
Ph.D., Chief Executive Officer of Amunix. "Existing recombinant blood
factor products require frequent intravenous infusions and there is strong
medical need for products that can be dosed less frequently and more
conveniently, and used prophylactically. In addition to further validating our
XTEN technology platform, this collaboration with Biogen Idec demonstrates the
potential of the Amunix XTEN technology for recombinant products that require
manufacturing in mammalian cells."